Encapsulating resin composition and semiconductor device

Abstract

To provide a sealing resin composition which is excellent in concealment property and visibility of printing by a laser marking method.SOLUTION: A sealing resin composition contains an epoxy resin, a curing agent, an inorganic filler and a coloring agent, is formed into a cured product with a thickness of 60 μm, and has a color difference ΔE0 from a coordinate (L*=0, a*=0 and b*=0) in a CIE 1976 (L*, a* and b*) color space on the surface of the cured product of 36 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to an encapsulating resin composition and a semiconductor device. [Background technology]

[0002] As electronic devices become lighter, thinner, and smaller, semiconductor packages are becoming smaller and thinner. The semiconductor packages described above are obtained by encapsulating semiconductor elements with a thermosetting resin encapsulant, and as semiconductor packages become thinner, the encapsulating resin layer that encapsulates the semiconductor elements is also becoming thinner.

[0003] In resin-sealed semiconductor packages, various types of identification information, such as manufacturing lot numbers and logos, are printed on the surface of the encapsulating resin layer. Laser marking is known as one method of printing on the surface of the encapsulating resin layer. Laser marking is a technology in which the surface of the encapsulating resin layer is scraped away with laser light to print. Laser marking directly engraves the encapsulating resin layer, eliminating the need for additional processes such as cleaning, resulting in higher production efficiency than printing methods and improved durability of the printed area.

[0004] Examples of encapsulating resin compositions that take laser marking properties into consideration include compositions disclosed in Patent Documents 1 to 3. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-278959 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-113566 [Patent Document 3] Japanese Patent Application Publication No. 2018-162351 Summary of the Invention [Problem to be solved by the invention]

[0006] As the sealing resin layer becomes thinner, the semiconductor element becomes more easily visible, which may result in poor appearance of the semiconductor device. Furthermore, when the encapsulating resin layer that encapsulates the semiconductor element is thinned, the thickness of the portion of the encapsulating resin layer located above the semiconductor element is also thinned. Therefore, when the portion of the encapsulating resin layer located above the semiconductor element is printed by a laser marking method, the encapsulating resin layer above the semiconductor element may become even thinner or the semiconductor element may be exposed, which may prevent the encapsulating resin layer from functioning properly. Therefore, the depth to which the encapsulating resin layer can be scraped off for printing is limited, which may reduce the visibility of various identification information printed on the semiconductor element. One aspect of the present disclosure has been made in view of the above-described conventional circumstances, and an object of the present disclosure is to provide an encapsulating resin composition that is excellent in hiding property and visibility of printing by a laser marking method, and a semiconductor device using the same. [Means for solving the problem]

[0007] Specific means for achieving the above object are as follows. <1> Contains an epoxy resin, a curing agent, an inorganic filler, and a colorant, When the cured product has a thickness of 60 μm, the CIE 1976 (L * , a * , b * ) color space coordinates (L * =0, a * =0, b * =0) is 36 or less. <2> The color difference ΔE between the surface of the cured product and an exposed portion formed by scraping the surface of the cured product to a depth of 10 μm in the thickness direction of the cured product is 3.1 or more. <1> The encapsulating resin composition according to claim 1. <3> The volume average particle size of the inorganic filler is 20 μm or less. <1> or <2> The encapsulating resin composition according to claim 1. <4> A semiconductor element and a device for sealing the semiconductor element <1> ~ <3> 10. A semiconductor device comprising: a cured product of the encapsulating resin composition according to any one of claims 1 to 9. <5> The average thickness of the cured product on the semiconductor element is 100 μm or less. <4> The semiconductor device according to claim 1. [Effects of the Invention]

[0008] According to one embodiment of the present disclosure, it is possible to provide an encapsulating resin composition that is excellent in hiding property and visibility of printing by a laser marking method, and a semiconductor device using the same. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments for carrying out the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present disclosure.

[0010] In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, each component may contain multiple substances corresponding to the component. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, the particles corresponding to each component may contain multiple types of particles. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified. In the present disclosure, the terms "layer" and "film" include cases where the layer or film is formed over the entire area when the area in which the layer or film is present is observed, as well as cases where the layer or film is formed over only a portion of the area.

[0011] <Sealing resin composition> The encapsulating resin composition of the present disclosure contains an epoxy resin, a curing agent, an inorganic filler, and a colorant, and when cured to a thickness of 60 μm, the surface of the cured product has a CIE 1976(L * , a * , b * ) color space coordinates (L * =0, a * =0, b * =0) is 36 or less. The present inventors have discovered that when a cured product having a thickness of 60 μm is formed, the color difference ΔE0 on the surface of the cured product is set to 36 or less, thereby improving hiding power and visibility of printing by laser marking, and have completed the present invention.

[0012] In the present disclosure, the color difference ΔE0 is measured as follows. The encapsulating resin composition of the present disclosure is heat-cured to obtain a cured product having a thickness of 60 μm. Note that the cured product having a thickness of 60 μm may have a region having a thickness of 60 μm, and the cured product does not necessarily have to be a sheet-like cured product having a thickness of 60 μm throughout. A cured product with a thickness of 60 μm can be produced by methods such as compression molding or transfer molding. For example, a compression molding machine PMC1040-S (TOWA Corporation) is used, and an amount of encapsulating resin composition corresponding to the volume of the molded product is placed between upper and lower molds, and the mixture is cured by automatic heating and pressing to obtain a cured product. The molding conditions are appropriately set depending on the composition of the encapsulating resin composition. The color difference ΔE0 of the resulting cured product having a thickness of 60 μm is determined by the following method. Using CM-3600A (Konica Minolta, Inc.) * a * b * Color space coordinates (L1* , a1 * , b1 * ) is measured. The measured value L1 * , a1 * and b1 * Using the following formula, the coordinates (L * =0, a * =0, b * = 0) and calculate the color difference ΔE0. ΔE0=[(L1 * -0) 2 +(a1 * -0) 2 +(b1 * -0) 2 ] 1 / 2 The thickness of the cured product at a measurement point can be measured by observing the cross section of the measurement target using an electron microscope.

[0013] In the present disclosure, the color difference ΔE0 is 36 or less, preferably 35 or less, more preferably 26 or less, and even more preferably 23 or less. In the present disclosure, the lower limit of the color difference ΔE0 is not particularly limited, and may be 15 or more.

[0014] In the present disclosure, the color difference ΔE between the surface of a 60 μm-thick cured product and an exposed portion obtained by scraping the surface of the cured product to a depth of 10 μm in the thickness direction of the cured product is preferably 3.1 or more, more preferably 3.9 or more, and even more preferably 4.6 or more. A color difference ΔE of 3.1 or more tends to further improve visibility. In the present disclosure, the upper limit of the color difference ΔE is not particularly limited, and may be 10 or less.

[0015] In the present disclosure, the method for measuring the color difference ΔE is as follows. A marking measuring 25 mm x 25 mm and 10 μm deep is formed on the cured product obtained as described above by laser marking. The laser mark can be formed, for example, using an EnergyHYBRID H20 from Gravotech Co., Ltd. The conditions for forming the laser mark are appropriately set in consideration of the surface condition of the cured product, the composition of the encapsulating resin composition, etc. The depth of the laser mark can be measured by observing the cross section of the object to be measured using an electron microscope. The areas of the cured product that had not been laser marked were laser marked using a CM-3600A (Konica Minolta). * a * b * Color space coordinates (L2 * , a2 * , b2 * Next, the color space coordinates (L3 * , a3 * , b3 * ) is measured. The measured value L2 * , a2 * , b2 * , L3 * , a3 * and b3 * Using this, calculate the color difference ΔE from the laser marked area using the following formula. ΔE=[(L2 * -L3 * ) 2 +(a2 * -a3 * ) 2 +(b2 * -b3 * ) 2 ] 1 / 2

[0016] Hereinafter, each component constituting the encapsulating resin composition of the present disclosure will be described.

[0017] (epoxy resin) The encapsulating resin composition of the present disclosure contains an epoxy resin. The type of epoxy resin is not particularly limited as long as it has two or more epoxy groups in one molecule. Specifically, novolac epoxy resins (phenol novolac epoxy resins, orthocresol novolac epoxy resins, etc.) are obtained by epoxidizing novolac resins obtained by condensing or co-condensing, under an acid catalyst, at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, etc., and naphthol compounds such as α-naphthol, β-naphthol, dihydroxynaphthalene, etc., with an aliphatic aldehyde compound such as formaldehyde, acetaldehyde, propionaldehyde, etc.; triphenylmethane epoxy resins are obtained by epoxidizing triphenylmethane phenolic resins obtained by condensing or co-condensing, under an acid catalyst, the above phenolic compounds with aromatic aldehyde compounds such as benzaldehyde, salicylaldehyde, etc.; and novolac resins obtained by co-condensing, under an acid catalyst, the above phenolic compounds and naphthol compounds with an aldehyde compound, etc., are epoxidized. diphenylmethane-type epoxy resins, which are diglycidyl ethers of bisphenol A, bisphenol F, etc.; biphenyl-type epoxy resins, which are diglycidyl ethers of alkyl-substituted or unsubstituted biphenols; stilbene-type epoxy resins, which are diglycidyl ethers of stilbene-based phenolic compounds; sulfur-containing epoxy resins, which are diglycidyl ethers of bisphenol S, etc.; epoxy resins, which are glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ester-type epoxy resins, which are glycidyl esters of polycarboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidylamine-type epoxy resins, in which the active hydrogen bonded to the nitrogen atom of aniline, diaminodiphenylmethane, isocyanuric acid, etc. is substituted with a glycidyl group; and dicyclopentadiene-type epoxy resins, which are epoxidized co-condensation resins of dicyclopentadiene and phenolic compounds.Alicyclic epoxy resins such as vinylcyclohexene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, which are produced by epoxidizing the olefin bonds in the molecule; paraxylylene-modified epoxy resins, which are glycidyl ethers of paraxylylene-modified phenolic resins; metaxylylene-modified epoxy resins, which are glycidyl ethers of metaxylylene-modified phenolic resins; terpene-modified epoxy resins, which are glycidyl ethers of terpene-modified phenolic resins; and dicyclopentadiene-modified phenolic resins, which are glycidyl ethers of dicyclopentadiene-modified phenolic resins. Examples of suitable epoxy resins include pentadiene-modified epoxy resins, cyclopentadiene-modified epoxy resins, which are glycidyl ethers of cyclopentadiene-modified phenolic resins; polycyclic aromatic ring-modified epoxy resins, which are glycidyl ethers of polycyclic aromatic ring-modified phenolic resins; naphthalene-type epoxy resins, which are glycidyl ethers of naphthalene ring-containing phenolic resins; halogenated phenol novolac-type epoxy resins; hydroquinone-type epoxy resins; trimethylolpropane-type epoxy resins; linear aliphatic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid; and aralkyl-type epoxy resins obtained by epoxidizing aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins. Further examples of suitable epoxy resins include epoxidized silicone resins and aminophenol-type epoxy resins, which are glycidyl ethers of aminophenols. These epoxy resins may be used alone or in combination of two or more.

[0018] Among the above epoxy resins, from the viewpoint of a balance between heat resistance and fluidity, epoxy resins selected from the group consisting of biphenyl-type epoxy resins, stilbene-type epoxy resins, diphenylmethane-type epoxy resins, sulfur-atom-containing epoxy resins, novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, triphenylmethane-type epoxy resins, copolymer-type epoxy resins, and aralkyl-type epoxy resins (these are referred to as "specific epoxy resins"). The specific epoxy resins may be used alone or in combination of two or more.

[0019] When the epoxy resin contains a specific epoxy resin, the content of the specific epoxy resin is preferably 30% by mass or more, and more preferably 50% by mass or more, of the total epoxy resin, from the viewpoint of exhibiting the performance of the specific epoxy resin.

[0020] Among the specific epoxy resins, biphenyl-type epoxy resins, stilbene-type epoxy resins, diphenylmethane-type epoxy resins, and sulfur-atom-containing epoxy resins are more preferred from the viewpoint of fluidity, and dicyclopentadiene-type epoxy resins, triphenylmethane-type epoxy resins, and aralkyl-type epoxy resins are preferred from the viewpoint of heat resistance. Specific examples of preferred epoxy resins are shown below.

[0021] The biphenyl type epoxy resin is not particularly limited as long as it is an epoxy resin having a biphenyl skeleton. For example, an epoxy resin represented by the following general formula (II) is preferred. Among the epoxy resins represented by the following general formula (II), R 8 When the oxygen atom is substituted at the 4 and 4' positions, the 3, 3', 5, and 5' positions are methyl groups, and the other R 8 YX-4000H (Mitsubishi Chemical Corporation, product name) where R is a hydrogen atom, 8 4,4'-bis(2,3-epoxypropoxy)biphenyl, where R is a hydrogen atom, 8 When is a hydrogen atom and R 8 When the oxygen atom is substituted at the 4 and 4' positions, the 3, 3', 5, and 5' positions are methyl groups, and the other R 8is a hydrogen atom, YL-6121H (trade name, Mitsubishi Chemical Corporation) and the like are commercially available.

[0022] [ka]

[0023] In formula (II), R 8 represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aromatic group having 6 to 18 carbon atoms, and may all be the same or different. n is an average value and represents a number of 0 to 10.

[0024] The stilbene type epoxy resin is not particularly limited as long as it is an epoxy resin having a stilbene skeleton. For example, an epoxy resin represented by the following general formula (III) is preferred. Among the epoxy resins represented by the following general formula (III), R 9 When the oxygen atom is substituted at the 4 and 4' positions, the 3, 3', 5, and 5' positions are methyl groups, and the other R 9 is a hydrogen atom, and R 10 are all hydrogen atoms, and R 9 Three of the 3, 3', 5, and 5' positions are methyl groups, one is a t-butyl group, and the remaining R 9 is a hydrogen atom, and R 10 and mixtures of those in which all of the above are hydrogen atoms.

[0025] [ka]

[0026] In formula (III), R 9 and R 10 represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different from each other. n is an average value and represents a number of 0 to 10.

[0027] The diphenylmethane type epoxy resin is not particularly limited as long as it is an epoxy resin having a diphenylmethane skeleton. For example, an epoxy resin represented by the following general formula (IV) is preferred. Among the epoxy resins represented by the following general formula (IV), R 11 are all hydrogen atoms, and R 12 When the oxygen atom is substituted at the 4 and 4' positions, the 3, 3', 5, and 5' positions are methyl groups, and the other R 12 YSLV-80XY (Nippon Steel Chemical & Material Co., Ltd., product name) in which is a hydrogen atom is commercially available.

[0028] [ka]

[0029] In formula (IV), R 11 and R 12 represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different from each other. n is an average value and represents a number of 0 to 10.

[0030] The sulfur atom-containing epoxy resin is not particularly limited as long as it is an epoxy resin containing a sulfur atom. For example, an epoxy resin represented by the following general formula (V) can be mentioned. Among the epoxy resins represented by the following general formula (V), R 13 When the oxygen atom is substituted at the 4 and 4' positions, the 3 and 3' positions are t-butyl groups, and the 6 and 6' positions are methyl groups. 13 YSLV-120TE (Nippon Steel Chemical & Material Co., Ltd., product name) in which is a hydrogen atom is commercially available.

[0031] [ka]

[0032] In formula (V), R 13represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different from each other. n is an average value and represents a number of 0 to 10.

[0033] The novolac epoxy resin is not particularly limited as long as it is an epoxy resin obtained by epoxidizing a novolac phenolic resin. For example, epoxy resins obtained by epoxidizing a novolac phenolic resin such as a phenol novolac resin, a cresol novolac resin, or a naphthol novolac resin using a method such as glycidyl etherification are preferred, and epoxy resins represented by the following general formula (VI) are more preferred. Among the epoxy resins represented by the following general formula (VI), R 14 are all hydrogen atoms, and R 15 is a methyl group, and i=1; ESCN-190 and ESCN-195 (product names, Sumitomo Chemical Co., Ltd.); 14 N-770 and N-775 (trade names, DIC Corporation) in which all of R are hydrogen atoms and i=0; 14 are all hydrogen atoms, and the part where i = 0 and the part where i = 1 and R 15 YDAN-1000-10C (Nippon Steel Chemical & Material Co., Ltd., product name), a styrene-modified phenolic novolac epoxy resin having a moiety where R is -CH(CH3)-Ph; 14 are all hydrogen atoms, i=1, and R 15 is a methyl group, and i=2 and R 15 A benzyl group-modified cresol novolac epoxy resin having one methyl group and one benzyl group is commercially available.

[0034] [ka]

[0035] In formula (VI), R 14 R represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. 15represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i independently represents an integer of 0 to 3. n is an average value and represents a number of 0 to 10.

[0036] The dicyclopentadiene-type epoxy resin is not particularly limited as long as it is an epoxy resin obtained by epoxidizing a compound having a dicyclopentadiene skeleton as a raw material. For example, an epoxy resin represented by the following general formula (VII) is preferred. Among the epoxy resins represented by the following general formula (VII), HP-7200 (trade name, DIC Corporation), in which i = 0, is commercially available.

[0037] [ka]

[0038] In formula (VII), R 16 represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i independently represents an integer of 0 to 3. n is an average value and represents a number of 0 to 10.

[0039] The triphenylmethane epoxy resin is not particularly limited as long as it is an epoxy resin made from a compound having a triphenylmethane skeleton. For example, an epoxy resin obtained by glycidyl etherifying a triphenylmethane phenolic resin obtained from an aromatic aldehyde compound and a phenolic compound is preferred, and an epoxy resin represented by the following general formula (VIII) is more preferred. Among the epoxy resins represented by the following general formula (VIII), 1032H60 (Mitsubishi Chemical Corporation, trade name) and EPPN-502H (Nippon Kayaku Co., Ltd., trade name), in which i is 0 and k is 0, are commercially available.

[0040] [ka]

[0041] In formula (VIII), R 17 and R 18represents a monovalent organic group having 1 to 18 carbon atoms, and may all be the same or different. Each i independently represents an integer of 0 to 3, and each k independently represents an integer of 0 to 4. n is an average value and represents a number of 0 to 10.

[0042] The copolymerized epoxy resin obtained by epoxidizing a novolac resin obtained from a naphthol compound, a phenol compound, and an aldehyde compound is not particularly limited as long as it is an epoxy resin made from a compound having a naphthol skeleton and a compound having a phenol skeleton as raw materials. For example, an epoxy resin obtained by glycidyl etherifying a novolac phenolic resin using a compound having a naphthol skeleton and a compound having a phenol skeleton is preferred, and an epoxy resin represented by the following general formula (IX) is more preferred. Among the epoxy resins represented by the following general formula (IX), R 21 is a methyl group, i is 1, j is 0, and k is 0, and NC-7300 (trade name, Nippon Kayaku Co., Ltd.) is available as a commercially available product.

[0043] [ka]

[0044] In formula (IX), R 19 ~R 21 represents a monovalent organic group having 1 to 18 carbon atoms, and may all be the same or different. Each i independently represents an integer of 0 to 3, each j independently represents an integer of 0 to 2, and each k independently represents an integer of 0 to 4. Each l and m is an average value and a number of 0 to 10, and (l+m) represents a number of 0 to 10. The terminal of the epoxy resin represented by formula (IX) is either formula (IX-1) or (IX-2) below. In formulas (IX-1) and (IX-2), R 19 ~R 21 , i, j and k are defined as R 19 ~R 21 The definitions of i, j, and k are the same as those of i, j, and k. n is 1 (when the bond is formed via a methylene group) or 0 (when the bond is not formed via a methylene group).

[0045] [ka]

[0046] Examples of the epoxy resin represented by the general formula (IX) include random copolymers containing l structural units and m structural units randomly, alternating copolymers containing them alternately, copolymers containing them regularly, block copolymers containing them in blocks, etc. Any of these may be used alone or in combination of two or more.

[0047] Another preferred copolymer epoxy resin is Epiclon HP-5000 (trade name, DIC Corporation), a methoxynaphthalene-cresol-formaldehyde co-condensation epoxy resin containing the following two structural units in a random, alternating, or block order: In the following general formula, n and m each represent an average value and are numbers from 0 to 10, and (n+m) represents a number from 0 to 10, preferably n and m each represent an average value and are numbers from 1 to 9, and (n+m) represents a number from 2 to 10.

[0048] [ka]

[0049] The aralkyl epoxy resin is not particularly limited as long as it is an epoxy resin made from a phenolic resin synthesized from at least one selected from the group consisting of phenolic compounds such as phenol and cresol and naphthol compounds such as naphthol and dimethylnaphthol, and dimethoxyparaxylene, bis(methoxymethyl)biphenyl, or a derivative thereof. For example, epoxy resins obtained by glycidyl etherifying a phenolic resin synthesized from at least one selected from the group consisting of phenolic compounds such as phenol and cresol and naphthol compounds such as naphthol and dimethylnaphthol, and dimethoxyparaxylene, bis(methoxymethyl)biphenyl, or a derivative thereof are preferred, and epoxy resins represented by the following general formulas (X) and (XI) are more preferred.

[0050] Among the epoxy resins represented by the following general formula (X), those in which i is 0 and R 38 is a hydrogen atom, i is 0, and R 38 is a hydrogen atom and all R 8 CER-3000 (trade name, Nippon Kayaku Co., Ltd.), which is a mixture of an epoxy resin in which l is a hydrogen atom and an epoxy resin in which k is a hydrogen atom at a mass ratio of 80:20, is commercially available. Furthermore, among the epoxy resins represented by the following general formula (XI), ESN-175 (trade name, Nippon Steel Chemical & Material Co., Ltd.), in which l is 0, j is 0, and k is 0, is commercially available.

[0051] [ka]

[0052] In formulas (X) and (XI), R 38 R represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. 37 , R 39 ~R 41 represents a monovalent organic group having 1 to 18 carbon atoms, and may all be the same or different. Each i is independently an integer of 0 to 3, each j is independently an integer of 0 to 2, each k is independently an integer of 0 to 4, and each l is independently an integer of 0 to 4. Each n is an average value and is independently a number of 0 to 10.

[0053] R in the above general formulas (II) to (XI) 8 ~R 21 and R 37 ~R 41 In the formula (II), "all of them may be the same or different" means, for example, that 8 to 88 R 8 This means that all of the R may be the same or different. 9 ~R 21 and R 37 ~R 41In addition, the numbers of R may all be the same or different. 8 ~R 21 and R 37 ~R 41 may be the same or different. For example, R 9 and R 10 may all be the same or different. Furthermore, the monovalent organic group having 1 to 18 carbon atoms in the general formulae (III) to (XI) is preferably an alkyl group or an aryl group.

[0054] In the general formulas (II) to (XI), n is an average value, and each independently is preferably in the range of 0 to 10. When n is 10 or less, the melt viscosity of the resin component does not become too high, and the viscosity of the encapsulating resin composition during melt molding tends to decrease, and the occurrence of filling defects, deformation of bonding wires (gold wires connecting elements to leads), etc. is more preferably set in the range of 0 to 4.

[0055] Specific examples of preferred epoxy resins that can be used in the encapsulating resin composition have been described above in accordance with the general formulas (II) to (XI). More specific preferred epoxy resins include 4,4'-bis(2,3-epoxypropoxy)-3,3',5,5'-tetramethylbiphenyl from the viewpoint of heat resistance, and 4,4'-bis(2,3-epoxypropoxy)-biphenyl from the viewpoint of moldability and heat resistance.

[0056] The epoxy equivalent of the epoxy resin is not particularly limited. From the viewpoint of a balance of various properties such as moldability, heat resistance, and electrical reliability, the epoxy equivalent of the epoxy resin is preferably 60 g / eq to 1000 g / eq, and more preferably 80 g / eq to 500 g / eq.

[0057] The epoxy resin may be liquid or solid. When the epoxy resin is solid, the softening point or melting point of the epoxy resin is not particularly limited. From the viewpoints of moldability and heat resistance, it is preferably 40°C to 180°C, and from the viewpoint of handleability during preparation of the encapsulating resin composition, it is more preferably 50°C to 130°C. In the present disclosure, the softening point refers to a value measured by the ring and ball method of JIS K 7234:1986. In the present disclosure, the melting point refers to a value measured in accordance with the visual method of JIS K 0064:1992.

[0058] The content of the epoxy resin in the encapsulating resin composition is preferably 0.5 to 60% by mass, more preferably 2 to 50% by mass, from the viewpoints of strength, fluidity, heat resistance, moldability, etc.

[0059] (hardening agent) The encapsulating resin composition of the present disclosure contains a curing agent. The type of curing agent is not particularly limited and can be selected from those commonly used as curing agents for epoxy resins. The curing agent may be used alone or in combination of two or more. Examples of the curing agent include amine-based curing agents, phenol-based curing agents, and acid anhydride-based curing agents. Among these, phenol-based curing agents or amine-based curing agents are preferred from the viewpoint of heat resistance. Examples of phenolic curing agents include phenolic resins and polyhydric phenolic compounds having two or more phenolic hydroxyl groups per molecule. Specific examples include polyhydric phenolic compounds such as resorcinol, catechol, bisphenol A, bisphenol F, and substituted or unsubstituted biphenols; novolak-type phenolic resins obtained by condensing or co-condensing at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene with an aldehyde compound such as formaldehyde, acetaldehyde, or propionaldehyde under an acidic catalyst; and phenolic compounds synthesized from the above-mentioned phenolic compounds and dimethoxyparaxylene, bis(methoxymethyl)biphenyl, or the like. Examples of suitable curing agents include aralkyl-type phenolic resins such as aryl aralkyl resins and naphthol aralkyl resins; paraxylylene-modified phenolic resins; metaxylylene-modified phenolic resins; melamine-modified phenolic resins; terpene-modified phenolic resins; dicyclopentadiene-type phenolic resins and dicyclopentadiene-type naphthol resins synthesized by copolymerization of the above-mentioned phenolic compounds with dicyclopentadiene; cyclopentadiene-modified phenolic resins; polycyclic aromatic ring-modified phenolic resins; biphenyl-type phenolic resins; triphenylmethane-type phenolic resins obtained by condensation or co-condensation of the above-mentioned phenolic compounds with aromatic aldehyde compounds such as benzaldehyde and salicylaldehyde under an acidic catalyst; and phenolic resins obtained by copolymerization of two or more of these. These phenolic curing agents may be used alone or in combination of two or more.

[0060] Among phenolic curing agents, from the viewpoint of heat resistance, at least one selected from the group consisting of aralkyl phenolic resins, dicyclopentadiene phenolic resins, triphenylmethane phenolic resins, copolymerized phenolic resins of triphenylmethane phenolic resins and aralkyl phenolic resins, and novolac phenolic resins (these are referred to as "specific phenolic curing agents"). The specific phenolic curing agents may be used alone or in combination of two or more.

[0061] When the phenolic curing agent contains a specific phenolic curing agent, the content of the specific phenolic curing agent is preferably 30% by mass or more, and more preferably 50% by mass or more, of the total phenolic curing agent, from the viewpoint of fully exhibiting its performance.

[0062] Examples of aralkyl phenolic resins include phenol aralkyl resins and naphthol aralkyl resins synthesized from a phenolic compound and dimethoxyparaxylene, bis(methoxymethyl)biphenyl, etc. The aralkyl phenolic resin may be further copolymerized with other phenolic resins. Examples of copolymerized aralkyl phenolic resins include copolymerized phenolic resins of triphenylmethane phenolic resin and aralkyl phenolic resin, copolymerized phenolic resins of salicylaldehyde phenolic resin and aralkyl phenolic resin, and copolymerized phenolic resins of novolac phenolic resin and aralkyl phenolic resin.

[0063] The aralkyl phenolic resin is not particularly limited as long as it is a phenolic resin synthesized from at least one compound selected from the group consisting of phenol compounds and naphthol compounds, and dimethoxy-para-xylene, bis(methoxymethyl)biphenyl, or a derivative thereof. For example, phenolic resins represented by the following general formulas (XII) to (XIV) are preferred.

[0064] [ka]

[0065] In formulas (XII) to (XIV), R 23 R represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. 22 , R 24 , R 25 and R 28 R represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. 26 and R 27 represents a hydroxyl group or a monovalent organic group having 1 to 18 carbon atoms, and may all be the same or different. Each i is independently an integer of 0 to 3, each j is independently an integer of 0 to 2, each k is independently an integer of 0 to 4, and each p is independently an integer of 0 to 4. Each n is an average value and is independently a number of 0 to 10.

[0066] Among the phenolic resins represented by the general formula (XII), i is 0 and R 23 MEH-7851 (product name, Meiwa Kasei Co., Ltd.), in which all are hydrogen atoms, is commercially available.

[0067] Among the phenolic resins represented by the general formula (XIII) above, XL-225, XLC (Mitsui Chemicals, Inc., trade name), MEH-7800 (Meiwa Chemical Industry Co., Ltd., trade name), etc., in which i is 0 and k is 0, are commercially available.

[0068] Among the phenolic resins represented by the general formula (XIV), SN-170 (trade name, Nippon Steel Chemical & Material Co., Ltd.), in which j is 0, k is 0, and p is 0, and R 27 is a hydroxyl group and p is 0, and SN-395 (trade name, Nippon Steel Chemical & Material Co., Ltd.) is available as a commercially available product.

[0069] The dicyclopentadiene-type phenolic resin is not particularly limited as long as it is a phenolic resin obtained from a compound having a dicyclopentadiene skeleton as a raw material. For example, a phenolic resin represented by the following general formula (XV) is preferred. Among the phenolic resins represented by the following general formula (XV), phenolic resins in which i is 0 are commercially available.

[0070] [ka]

[0071] In formula (XV), R 29 represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i independently represents an integer of 0 to 3. n is an average value and represents a number of 0 to 10.

[0072] The triphenylmethane type phenolic resin is not particularly limited as long as it is a phenolic resin obtained from an aromatic aldehyde compound as a raw material. For example, a phenolic resin represented by the following general formula (XVI) is preferred.

[0073] Among the phenolic resins represented by the following general formula (XVI), MEH-7500 (trade name, Meiwa Kasei Co., Ltd.), in which i and k are 0, is commercially available.

[0074] [ka]

[0075] In formula (XVI), R 30 and R 31 represents a monovalent organic group having 1 to 18 carbon atoms, and may all be the same or different. Each i is independently an integer of 0 to 3, and each k is independently an integer of 0 to 4. n is an average value and is a number of 0 to 10.

[0076] The copolymerized phenolic resin of a triphenylmethane type phenolic resin and an aralkyl type phenolic resin is not particularly limited as long as it is a copolymerized phenolic resin of a phenolic resin obtained from a compound having a benzaldehyde skeleton as a raw material and an aralkyl type phenolic resin. For example, a phenolic resin represented by the following general formula (XVII) is preferred.

[0077] Among the phenolic resins represented by the following general formula (XVII), HE-510 (trade name, Air Water Chemical Co., Ltd.), in which i is 0, k is 0, and q is 0, is commercially available.

[0078] [ka]

[0079] In formula (XVII), R 32 ~R 34 represents a monovalent organic group having 1 to 18 carbon atoms, and may all be the same or different. Each i is independently an integer of 0 to 3, each k is independently an integer of 0 to 4, and each q is independently an integer of 0 to 5. Each l and m is an average value and independently a number of 0 to 11, provided that the sum of l and m is a number of 1 to 11.

[0080] The novolac phenolic resin is not particularly limited as long as it is a phenolic resin obtained by condensing or co-condensing at least one phenolic compound selected from the group consisting of phenol compounds and naphthol compounds with an aldehyde compound in the presence of an acid catalyst. For example, a phenolic resin represented by the following general formula (XVIII) is preferred.

[0081] Among the phenolic resins represented by the following general formula (XVIII), those in which i is 0 and R 35 are all hydrogen atoms, such as Tamanol 758 and 759 (trade names, Arakawa Chemical Industries, Ltd.) and H-4 (trade name, Meiwa Chemical Industry Co., Ltd.).

[0082] [ka]

[0083] In formula (XVIII), R 35 R represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. 36 represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i independently represents an integer of 0 to 3. n is an average value and represents a number of 0 to 10.

[0084] R in the above general formulas (XII) to (XVIII) 22 ~R 36 The expression "may be the same or different" means, for example, that i R 22 This means that all of the R may be the same or different from each other. 23 ~R 36 In addition, the numbers of R may be the same or different from each other. 22 ~R 36 may be the same or different. For example, R 22 and R 23 may be the same or different, and R 30 and R 31 may all be the same or different.

[0085] In the general formulas (XII) to (XVIII), n is preferably in the range of 0 to 10. If it is 10 or less, the melt viscosity of the resin component will not be too high, and the viscosity of the encapsulating resin composition during melt molding will also be low, making it less likely that filling defects, deformation of bonding wires (gold wires connecting elements to leads), etc. will occur. The average n in one molecule is preferably set in the range of 0 to 4.

[0086] Specific examples of amine curing agents include aliphatic amine compounds such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, and 4,4'-diamino-dicyclohexylmethane, aromatic amine compounds such as diethyltoluenediamine, 3,3'-diethyl-4,4'-diaminodiphenylmethane, dimethylthiotoluenediamine, and 2-methylaniline, imidazole compounds such as imidazole, 2-methylimidazole, 2-ethylimidazole, and 2-isopropylimidazole, and imidazoline compounds such as imidazoline, 2-methylimidazoline, and 2-ethylimidazoline. Among these, aromatic amine compounds are preferred from the viewpoint of storage stability, and diethyltoluenediamine, 3,3'-diethyl-4,4'-diaminodiphenylmethane, and dimethylthiotoluenediamine are more preferred.

[0087] The functional group equivalent of the curing agent (hydroxyl group equivalent in the case of a phenolic curing agent, active hydrogen equivalent in the case of an amine-based curing agent) is not particularly limited. From the viewpoint of the balance of various properties such as moldability, heat resistance, and electrical reliability, it is preferably 10 g / eq to 1000 g / eq, and more preferably 30 g / eq to 500 g / eq. The hydroxyl equivalent weight in the case of a phenolic curing agent is a value calculated based on the hydroxyl value measured in accordance with JIS K 0070:1992, and the active hydrogen equivalent weight in the case of an amine curing agent is a value calculated based on the amine value measured in accordance with JIS K 7237:1995.

[0088] When the curing agent is solid, the softening point or melting point is not particularly limited, but is preferably 40°C to 180°C from the viewpoint of moldability and heat resistance, and more preferably 50°C to 130°C from the viewpoint of handleability during production of the encapsulating resin composition.

[0089] The equivalent ratio of the epoxy resin to the curing agent (molar number of epoxy groups in the resin / molar number of active hydrogens in the curing agent) is not particularly limited, but from the viewpoint of minimizing the amount of unreacted components, it is preferably, for example, 0.7 to 1.6, more preferably 0.8 to 1.4, and even more preferably 0.9 to 1.2.

[0090] (curing accelerator) The encapsulating resin composition may contain a curing accelerator. The type of the curing accelerator is not particularly limited and can be selected depending on the type of epoxy resin, the desired properties of the encapsulating resin composition, and the like.

[0091] Specifically, diazabicycloalkenes such as 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), cyclic amidine compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-heptadecylimidazole, derivatives of the cyclic amidine compounds, phenol novolac salts of the cyclic amidine compounds or their derivatives, and the combination of these compounds with maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone, diazofuran, compounds having intramolecular polarization obtained by adding a compound having a π bond, such as phenylmethane; cyclic amidinium compounds such as the tetraphenylborate salt of DBU, the tetraphenylborate salt of DBN, the tetraphenylborate salt of 2-ethyl-4-methylimidazole, and the tetraphenylborate salt of N-methylmorpholine; tertiary amine compounds such as pyridine, triethylamine, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; derivatives of the above tertiary amine compounds; ammonium salt compounds such as tetra-n-butylammonium acetate, tetra-n-butylammonium phosphate, tetraethylammonium acetate, tetra-n-hexylammonium benzoate, and tetrapropylammonium hydroxide;organic phosphines such as primary phosphines such as ethylphosphine and phenylphosphine; secondary phosphines such as dimethylphosphine and diphenylphosphine; and tertiary phosphines such as triphenylphosphine, diphenyl(p-tolyl)phosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, tris(alkylalkoxyphenyl)phosphine, tris(dialkylphenyl)phosphine, tris(trialkylphenyl)phosphine, tris(tetraalkylphenyl)phosphine, tris(dialkoxyphenyl)phosphine, tris(trialkoxyphenyl)phosphine, tris(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkylarylphosphine, alkyldiarylphosphine, trinaphthylphosphine, and tris(benzyl)phosphine; phosphine compounds such as complexes of the above organic phosphines with organoborons; and complexes of the above organic phosphines or the above phosphine compounds with maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, compounds having intramolecular polarization obtained by adding a compound having a π bond, such as quinone compounds, such as 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, and anthraquinone, or diazophenylmethane; compounds having intramolecular polarization obtained by adding the above organic phosphines or the above phosphine compounds with 4-bromophenol, 3-bromophenol, 2-bromophenol, 4-chlorophenol, 3-chlorophenol, 2-chlorophenol, and 4-iodophenol; compounds with intramolecular polarization obtained by reacting halogenated phenol compounds such as phenol, 3-iodophenol, 2-iodophenol, 4-bromo-2-methylphenol, 4-bromo-3-methylphenol, 4-bromo-2,6-dimethylphenol, 4-bromo-3,5-dimethylphenol, 4-bromo-2,6-di-t-butylphenol, 4-chloro-1-naphthol, 1-bromo-2-naphthol, 6-bromo-2-naphthol, and 4-bromo-4'-hydroxybiphenyl, followed by a dehydrohalogenation step;Examples of the tetra-substituted phosphonium compounds include tetra-substituted phosphonium compounds such as tetraphenylphosphonium, tetraphenylborate salts of tetra-substituted phosphonium compounds such as tetraphenylphosphonium tetra-p-tolylborate, and salts of tetra-substituted phosphonium compounds with phenolic compounds; phosphobetaine compounds; and adducts of phosphonium compounds with silane compounds. Examples of curing accelerators that allow low-temperature curing include an adduct of tributylphosphine and 1,4-benzoquinone, dimethylaminopyridine, 2-ethyl-4-methylimidazole, 2-methylimidazole, and 1-benzyl-2-methylimidazole. The curing accelerators may be used alone or in combination of two or more.

[0092] When the encapsulating resin composition contains a curing accelerator, the content of the curing accelerator is preferably 0.1% by mass to 8% by mass with respect to the total amount of the epoxy resin and the curing agent.

[0093] (Inorganic filler) The encapsulating resin composition contains an inorganic filler.

[0094] The type of inorganic filler is not particularly limited. Specific examples include inorganic materials such as silica (e.g., spherical silica, crystalline silica), glass, alumina, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, titania, talc, clay, and mica. Inorganic fillers with flame retardant properties may also be used. Examples of inorganic fillers with flame retardant properties include aluminum hydroxide, magnesium hydroxide, composite metal hydroxides (e.g., magnesium-zinc composite hydroxide), and zinc borate. Among these, spherical silica is preferred from the viewpoint of reducing the linear expansion coefficient, and alumina is preferred from the viewpoint of high thermal conductivity. One type of inorganic filler may be used alone, or two or more types may be used in combination. Examples of the inorganic filler include powder, beads formed by spheroidizing powder, and fibers.

[0095] The content of the inorganic filler is not particularly limited. From the viewpoint of fluidity and strength, it is preferably 30 to 90% by volume, more preferably 35 to 85% by volume, and even more preferably 40 to 80% by volume of the entire encapsulating resin composition. When the content of the inorganic filler is 30% by volume or more of the entire encapsulating resin composition, the properties of the cured product, such as the thermal expansion coefficient, thermal conductivity, and elastic modulus, tend to be further improved. When the content of the inorganic filler is 90% by volume or less of the entire encapsulating resin composition, an increase in the viscosity of the encapsulating resin composition is suppressed, and the fluidity is further improved, tending to result in better moldability.

[0096] The average particle size of the inorganic filler is not particularly limited. For example, the volume average particle size is preferably 20 μm or less, more preferably 0.1 μm to 20 μm, even more preferably 0.2 μm to 18 μm, and particularly preferably 0.3 μm to 15 μm. When the volume average particle size is 20 μm or less, the ability to fill narrow gaps tends to be improved. Furthermore, when the volume average particle size is 0.1 μm or more, an increase in the viscosity of the encapsulating resin composition tends to be further suppressed. The volume average particle size of the inorganic filler can be measured as the volume average particle size (D50) using a laser diffraction scattering particle size distribution measuring device.

[0097] The maximum particle size (also referred to as cut point) of the inorganic filler is not particularly limited. From the viewpoint of filling into narrow gaps, the maximum particle size of the inorganic filler is preferably 150 μm or less, more preferably 75 μm or less, even more preferably 55 μm or less, and particularly preferably 20 μm or less.

[0098] From the viewpoint of the flowability of the encapsulating resin composition, the particle shape of the inorganic filler is preferably spherical rather than angular, and the particle size distribution of the inorganic filler is preferably wide.

[0099] (coloring agent) The encapsulating resin composition contains a colorant. Examples of colorants include known colorants such as carbon black, black titanium oxide, organic dyes, organic pigments, red lead, and red iron oxide. The content of the colorant can be appropriately selected depending on the purpose, etc. One type of colorant may be used alone, or two or more types may be used in combination. From the viewpoint of more effectively improving the printability by laser marking, it is preferable to contain at least black titanium oxide as a colorant, and it is more preferable to contain both black titanium oxide and carbon black.

[0100] Black titanium oxide is Ti n O (2n-1) (n is a positive integer). The black titanium oxide Ti n O (2n-1) It is preferable to use one in which n is 4 to 6 as the black titanium oxide. By making n 4 or more, it is likely that the dispersibility of the black titanium oxide in the encapsulating resin composition can be improved. On the other hand, by making n 6 or less, it is likely that the printability by laser marking method can be further improved. The encapsulating resin composition contains Ti4O7, Ti5O9, and Ti6O as the black titanium oxide. 11 It is preferable to include at least one of the following:

[0101] The black titanium oxide may be surface-treated with a known coupling agent such as a silane-based compound such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, or vinylsilane, a titanium-based compound, an aluminum chelate compound, or an aluminum / zirconium-based compound. When black titanium oxide that has been surface-treated with a coupling agent is used, the surface treatment of the black titanium oxide may be carried out together with the inorganic filler. The amount of coupling agent used for treatment is preferably 0.1 to 2 parts by mass, more preferably 0.12 to 1.6 parts by mass, and even more preferably 0.14 to 1.4 parts by mass, per 100 parts by mass of the total of the inorganic filler and black titanium oxide.

[0102] The average particle size of the black titanium oxide is not particularly limited. For example, the volume average particle size is preferably 0.01 μm to 2 μm, more preferably 0.02 μm to 1.5 μm, and even more preferably 0.03 μm to 1 μm. When the volume average particle size is 0.01 μm or more, an increase in viscosity of the encapsulating resin composition tends to be further suppressed. When the volume average particle size is 2 μm or less, the ability to fill narrow gaps tends to be further improved.

[0103] Examples of carbon black include acetylene black, ketjen black, thermal black, and furnace black.

[0104] From the viewpoint of improving printability by a laser marking method, the content of the colorant in the encapsulating resin composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.07% by mass or more, when the entire encapsulating resin composition is taken as 100% by mass. On the other hand, from the viewpoint of dielectric constant, the content of the colorant in the encapsulating resin composition is preferably 2.0% by mass or less, more preferably 1.8% by mass or less, and even more preferably 1.5% by mass or less, when the entire encapsulating resin composition is taken as 100% by mass. The content of the colorant may be 0.1% by mass or more, when the entire encapsulating resin composition is taken as 100% by mass.

[0105] When carbon black and black titanium oxide are used in combination as colorants, the mass-based content ratio of carbon black to black titanium oxide (carbon black / black titanium oxide) is preferably 0.01 to 10.0, more preferably 0.1 to 5.0, even more preferably 0.3 to 1.0, and particularly preferably 0.4 to 0.7.

[0106] (Various additives) In addition to the above-mentioned components, the encapsulating resin composition may contain various additives such as a coupling agent, an ion exchanger, a release agent, a flame retardant, and a stress relaxation agent, as exemplified below. The encapsulating resin composition may contain various additives known in the art, as needed, in addition to the additives exemplified below.

[0107] -Coupling agent- The encapsulating resin composition may contain a coupling agent to enhance adhesion between the epoxy resin and the inorganic filler, including known coupling agents such as silane-based compounds (e.g., epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, and vinylsilane), titanium-based compounds, aluminum chelate compounds, and aluminum / zirconium-based compounds.

[0108] When the encapsulating resin composition contains a coupling agent, the amount of the coupling agent is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 2.5 parts by mass, per 100 parts by mass of the inorganic filler. When the amount of the coupling agent is 0.05 parts by mass or more per 100 parts by mass of the inorganic filler, adhesion to the component tends to be further improved. When the amount of the coupling agent is 5 parts by mass or less per 100 parts by mass of the inorganic filler, moldability of the package tends to be further improved.

[0109] -Ion exchanger- The encapsulating resin composition may contain an ion exchanger. In particular, it is preferable to contain an ion exchanger from the viewpoint of improving the moisture resistance and high-temperature storage characteristics of the semiconductor device. The ion exchanger is not particularly limited, and conventionally known ion exchangers can be used. Specific examples include hydrotalcite compounds and hydrous oxides of at least one metal selected from the group consisting of magnesium, aluminum, titanium, zirconium, and bismuth. One type of ion exchanger may be used alone, or two or more types may be used in combination. Among these, hydrotalcites represented by the following general formula (A) are preferred.

[0110] Mg (1-X) AlX (OH)2(CO3) X / 2 ·mH2O ……(A) (0 < X ≤ 0.5, m is a positive number)

[0111] When the encapsulating resin composition contains an ion exchanger, its content is not particularly limited as long as it is sufficient to capture ions such as halogen ions. For example, it is preferably 0.1 to 30 parts by mass, more preferably 1 to 5 parts by mass, based on 100 parts by mass of the epoxy resin.

[0112] -Release agent- The encapsulating resin composition may contain a release agent from the viewpoint of obtaining good mold release properties with the mold during molding. The release agent is not particularly limited, and conventionally known ones can be used. Specifically, examples include higher fatty acids such as carnauba wax, montanic acid, and stearic acid, metal salts of higher fatty acids, ester waxes such as montanic acid esters, and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene. The release agent may be used alone or in combination of two or more kinds.

[0113] When the encapsulating resin composition contains a release agent, its content is preferably 0.01 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the epoxy resin. When the amount of the release agent is 0.01 parts by mass or more based on 100 parts by mass of the epoxy resin, mold release properties tend to be sufficiently obtained. When it is 15 parts by mass or less, better adhesion properties tend to be obtained.

[0114] -Flame retardant- The encapsulating resin composition may contain a flame retardant. The flame retardant is not particularly limited, and conventionally known ones can be used. Specifically, examples include organic or inorganic compounds containing a halogen atom, antimony atom, nitrogen atom, or phosphorus atom, metal hydroxides, etc. The flame retardant may be used alone or in combination of two or more kinds.

[0115] When the encapsulating resin composition contains a flame retardant, the content is not particularly limited as long as it is an amount sufficient to obtain the desired flame retardant effect, and is preferably 1 to 300 parts by mass, more preferably 2 to 150 parts by mass, per 100 parts by mass of the epoxy resin.

[0116] -Stress relief agent- The encapsulating resin composition may contain a stress relaxation agent such as silicone oil or silicone rubber particles. By including a stress relaxation agent, package warpage and package cracking can be further reduced. Examples of the stress relaxation agent include commonly used known stress relaxation agents (flexibilizers). Specific examples include thermoplastic elastomers such as silicone, styrene, olefin, urethane, polyester, polyether, polyamide, and polybutadiene; rubber particles such as NR (natural rubber), NBR (acrylonitrile-butadiene rubber), acrylic rubber, urethane rubber, and silicone powder; and rubber particles having a core-shell structure such as methyl methacrylate-styrene-butadiene copolymer (MBS), methyl methacrylate-silicone copolymer, and methyl methacrylate-butyl acrylate copolymer. One type of stress relaxation agent may be used alone, or two or more types may be used in combination. Among these, silicone-based stress relaxation agents are preferred. Examples of silicone-based stress relaxation agents include those having epoxy groups, those having amino groups, and polyether-modified versions of these.

[0117] (Method for preparing encapsulating resin composition) The method for preparing the encapsulating resin composition is not particularly limited. When the encapsulating resin composition is solid, a common method includes thoroughly mixing predetermined amounts of components using a mixer or the like, melt-kneading the mixture using a mixing roll, extruder, or the like, cooling, and pulverizing the mixture. More specifically, a method includes uniformly stirring and mixing predetermined amounts of the components described above, kneading the mixture using a kneader, roll, extruder, twin-screw extruder, or the like that has been preheated to 70°C to 140°C, cooling, and pulverizing the mixture. When the encapsulating resin composition is in a liquid state, a common method is to weigh out predetermined amounts of components and disperse and knead them using a three-roll mill, a crusher, a planetary mixer, a hard mixer, a homomixer, etc. In addition, a method using a masterbatch in which the components are pre-dispersed and pre-heated is preferred from the viewpoints of uniform dispersion and fluidity.

[0118] When the encapsulating resin composition is solid, its shape is not particularly limited, and examples thereof include powder, granules, tablets, pellets, etc. When the encapsulating resin composition is in the form of a tablet or pellet, it is preferable that the dimensions and mass thereof are set to be suitable for the molding conditions of the package from the viewpoint of handleability. When the encapsulating resin composition is in a liquid state, the viscosity at 25° C. is preferably less than 1000 Pa·s, more preferably 800 Pa·s or less, and further preferably 500 Pa·s or less. In this disclosure, the viscosity at 25°C refers to a value measured at a shear rate of 10 revolutions per minute using a rotational shear viscometer equipped with a cone plate (diameter 48 mm, cone angle 1°).

[0119] <Semiconductor device> The semiconductor device of the present disclosure includes a semiconductor element and a cured product of the encapsulating resin composition of the present disclosure that encapsulates the semiconductor element.

[0120] The method for encapsulating a semiconductor element using the encapsulating resin composition is not particularly limited, and known methods can be applied. Examples include transfer molding, compression molding, and injection molding. Among these, the compression molding is preferred from the viewpoint of thinning the encapsulating resin layer.

[0121] In the semiconductor device of the present disclosure, the average thickness of the cured product on the semiconductor element may be 100 μm or less. Because the encapsulating resin composition of the present disclosure has excellent hiding properties, the semiconductor element tends to be easily concealed even when the average thickness of the cured product on the semiconductor element is 100 μm or less. Furthermore, because the encapsulating resin composition of the present disclosure has excellent visibility of printing by laser marking, even when the average thickness of the cured product on the semiconductor element is 100 μm or less, a decrease in the visibility of various identification information printed on the semiconductor element tends to be suppressed. The average thickness of the cured product on the semiconductor element may be 80 μm or less, 60 μm or less, or 40 μm or less. Furthermore, the average thickness of the cured product on the semiconductor element may be 20 μm or more. The average thickness of the cured product can be measured by observing the cross section of the object to be measured using an electron microscope. The average thickness of the cured product is the arithmetic mean value of the thicknesses measured at five points.

[0122] Examples of semiconductor elements that constitute the semiconductor device of the present disclosure include diodes, transistors, thyristors, ICs (Integrated Circuits), and LSIs (Large Scale Integration). [Example]

[0123] The above embodiment will be specifically described below using examples, but the scope of the above embodiment is not limited to these examples.

[0124] -Preparation of encapsulating resin composition- An encapsulating resin composition was prepared by mixing the components shown in Table 1 in the amounts (parts by mass) shown in Table 1. Specifically, after mixing the materials, the mixture was kneaded in a twin-screw extruder with the internal temperature adjusted to 70°C to 100°C, cooled, and then pulverized to obtain an encapsulating resin composition. The details of each component are as follows:

[0125] Epoxy resin 1...Biphenyl type epoxy resin Epoxy resin 2...Diphenylmethane type epoxy resin (bisphenol A type epoxy resin) Hardener 1...Novolac phenolic resin Hardener 2: Aralkyl phenolic resin Curing accelerator: Phosphorus-based curing accelerator

[0126] Coupling agent: N-phenyl-3-aminopropyltrimethoxysilane

[0127] Colorant 1...Carbon black Colorant 2: Black titanium oxide with a volume average particle size of 0.5 μm that has not been surface-treated with a coupling agent Colorant 3: Black titanium dioxide (low alpha ray grade) with a volume average particle size of 0.5 μm that has not been surface treated with a coupling agent Colorant 4: Black titanium dioxide surface-treated with a coupling agent with a volume average particle size of 0.05 μm Colorant 5: Black titanium oxide with a volume average particle size of 0.05 μm that has not been surface-treated with a coupling agent

[0128] Inorganic filler 1: Spherical silica with a volume average particle size of 0.6 μm Inorganic filler 2: Spherical silica with a volume average particle size of 12 μm

[0129] -Measurement of ΔE0 and ΔE- The ΔE0 and ΔE of the encapsulating resin compositions described in the comparative examples and examples were measured by the method described above. The results are shown in Table 1.

[0130] -Transparency evaluation- A 10 mm x 10 mm x 400 μm silicon chip was mounted on a 240 mm x 70 mm glass epoxy substrate. Furthermore, a 30 μm thick polyimide tape was attached to the top surface of the silicon chip mounted on the substrate. The substrate with the silicon chip mounted was then encapsulated with the encapsulating resin composition described in the Comparative Examples and Examples so that the resin layer on the polyimide tape had a thickness of 40 μm, thereby obtaining an encapsulated molded product. The molding of the encapsulated molded product was carried out using a compression molding machine PMC1040-S (TOWA Corporation) at 175°C for 120 seconds. When the encapsulated molded product was viewed from above the resin layer, six evaluators visually evaluated whether the polyimide tape was visible or not, based on the following criteria. The results are shown in Table 1. A: Opaque B: It may be transparent depending on the viewing angle, but this does not pose a problem in practical use. C:Transparent

[0131] - Visibility evaluation - The letters "ABC" were marked on the cured products of the encapsulating resin compositions described in the Comparative Examples and Examples using Gravotech's EnergyHYBRID H20, with each letter measuring 1 mm x 1 mm. Marking conditions were appropriately set to achieve a marking depth of 10 μm. Six evaluators visually evaluated the resulting "ABC" letters according to the following criteria. The results are shown in Table 1. A: Good visibility B: Visible and no practical problems C: Not visible

[0132] [Table 1]

[0133] As is clear from the evaluation results in Table 1, the encapsulating resin compositions of the examples are excellent in hiding power and visibility of the markings obtained by the laser marking method.

Claims

1. Contains an epoxy resin, a curing agent, an inorganic filler, and a colorant, the colorant includes carbon black and black titanium oxide; a mass-based content ratio of the carbon black to the black titanium oxide (carbon black / black titanium oxide) of 0.4 to 0.7; An encapsulating resin composition, wherein when a cured product having a thickness of 60 μm is formed, the color difference ΔE0 of the surface of the cured product from coordinates (L*=0, a*=0, b*=0) in CIE 1976 (L*, a*, b*) color space is 23 or less.

2. 2. The encapsulating resin composition according to claim 1, wherein a color difference ΔE between a surface of the cured product and an exposed portion formed by scraping the surface of the cured product to a depth of 10 μm in the thickness direction of the cured product is 3.1 or more.

3. 3. The encapsulating resin composition according to claim 1, wherein the inorganic filler has a volume average particle size of 20 μm or less.

4. A semiconductor device comprising: a semiconductor element; and a cured product of the encapsulating resin composition according to any one of claims 1 to 3, which encapsulates the semiconductor element.

5. 5. The semiconductor device according to claim 4, wherein the average thickness of the cured product on the semiconductor element is 100 [mu]m or less.

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